Highly monodispersed CdS nanoparticles using polyvinyl pyrrolidone (PVP) as the capping agent were synthesised by chemical coprecipitation method. The surface-modified cadmium sulfide nanoparticles were found to be remarkably stable. In the presence of PVP, cubic phase with small grain size of CdS were observed in XRD. The peaks were identified to originate from (111), (220) and (311) planes of CdS, respectively. The crystallite size of the synthesised CdS nanoparticles was about 3 nm calculated from the (111) plane of XRD pattern and it was also confirmed through HRTEM. Morphology and elemental mapping of the synthesised nanoparticles were studied by SEM and EDX analyses. Increase in the band gap with decrease in the particle size was observed from the reflectance mode UV spectrum, which confirms the quantum confinement effect. From the photoluminescence studies, enhanced near-band-edge blue light emission and significantly reduced defect-related green emission were observed. Longitudinal optical (LO) phonon modes, corresponds to pure CdS were observed in Raman spectrum.

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First principle calculations on the magnetic properties and spin polarization of the B2 disordered Co 2 FeSi full Heusler alloy have been carried out along with that of ordered L2 1 structure. The linear augmented plane wave method, within the LDA?U approximation, gives the magnetic moment value as predicted by Slater-Pauling rule. A small band gap in the minority band structure around the vicinity of the Fermi level results in half-metallicity or 100 % spin polarization in L2 1 ordered structure. The calculations also showed that the half-metallicity vanishes at moderate percentages of B2 disorders due to creation of new states around the Fermi level in the minority DOS but at low and high levels of disorder, the half-metallicity was retained. The variation in the magnetic moments of Co 2 FeSi with change in the % disorder was attributed to the changes in the local magnetic moments of Co, Fe, and Si atoms which vary with change in % disorder.

In the crystal structure of the title salt, C6H8N+·C7H5O3 −, the anions and cations are linked by classical N—H⋯O hydrogen bonds. The anions are connected by pairs of C—H⋯O hydrogen bonds into inversion dimers and further linked by classical O—H⋯O hydrogen bonds. Weak π–π inter­actions [centroid–centroid distances = 3.740 (3) and 3.855 (3) Å] also occur. The dihedral angle between the CO2 − group and the benzene ring to which it is attached is 20.95 (8)°.